GB-A 2447611 describes a valve bag, and a method of manufacturing the same. The valve bag is manufactured by dispensing a first and second web of material, each having a ‘valve’ and an ‘open’ side; creating a combined web by contacting a lower side of the first web with an upper side of the second web; sealing the combined web together along a sealing line adjacent the valve side, the sealing process defining a valve portion; separating the first and second web at the open side and folding outwardly until a section of a lower side of the first web contacts an upper side of the second web; sealing together the contacting sections of the first and second web; and separating adjacent bag sections.
This valve bag was an improvement over its predecessors and their respective methods of manufacture. That is, it used conventional sealing and folding machines and allowed the manufacturer to vary the size and quantity of bags produced, such that the small valve bags for holding small items, such as nuts and bolts, were possible. Its predecessors were far more expensive to manufacture, such that only valve bags for larger quantities of products were economically viable.
It is therefore desirable to alleviate the above problem.